My card game application has been released in the App Store and various friends are now downloading it wanting to play. Most people can download the game, send invites to each other and start playing, however, there are two friends who are having trouble. I can send an invite to them to join a game or they can send an invite to me to join the game. In both cases the GKMatchmaker View Controller is displayed for the host player, then initially reports "Matching" and eventually reports "Connecting". However, the GKMatchmaker ViewController simply spins and spins indicating "Connecting" status only and the game never starts.
Using the iOS simulator I was able to verify the "didFind match" function is being called, however, the expectedPlayerCount is not 0 so the match never starts. Also, the "didChange state" function is never called to indicate the other player has "connected", so the match still never starts
Has anyone experience this issue and might know how to resolve it?
Notes:
1) Both friends can invite each other and play the game together, however, neither friend can invite me and play
2) My iPhone 8 has iOS 13.4 and both friends have iPhone 6 (iOS 12.4.5)
3) Using my iPhone 8, I can invite a third (different) player who has an iPhone 6 (iOS 12.4.5) succcessfully
4) Using an iPhone11 (iOS 13.3) I can invite either of the two friends successfully